Association of state-level intoxicated driving laws with firearm homicide and suicide

To determine if an association exists between the number of driving under the influence (DUI) convictions required to activate federal firearms prohibitions and annual firearm homicide and suicide rates by state.

Ecological cross-sectional study of all US states from 2013 to 2017. We collected DUI law data from Thomson Reuters Westlaw database and firearm mortality data from the Centers for Disease Control and Prevention Vital Statistics programme.

Five states had laws such that one or two DUI convictions could result in prohibitions to firearms access according to federal law. Four states had no legal framework that would restrict firearms access because of DUI convictions; the remaining states could activate federal restrictions at three or more DUI convictions. Firearm-specific homicide (victimisations) rates were 19% lower among women in states where federal restrictions of firearms access occurred after one or two DUI offences (incidence rate ratio (IRR) 0.81; 95% CI 0.64 to 1.01) and 18% lower in states with firearm prohibitions after three or more offences (IRR 0.82; 95% CI 0.71 to 0.95) compared with the states with no legal framework for prohibiting firearms after DUI convictions. There was no association between number of DUI activations and overall, or firearm-specific, suicide among the entire population (men and women) or among only women, or only men.

DUI penalties that activate federal firearms prohibitions may be one pathway to reduce firearm homicide of female victims.